Hi I have a weird problem with my A/C. my car is a 2003 ap1 with custom turbo kit hx35 with a full build motor and running Doctronic pro ecu
The problem started last year randomly.

When i Start the car with interior fan at off the ac clutch isnt engaged (which is normal)
If i set any fan speed on without activating a\c the ac clutch isnt enganged (which is normal)
If i set Ac On, it engage but even if i turn it off after a while, the clutch will stay engaged and fans will run until i shut off the car.... (which i think isnt normal)

I can clearly see when the ecu receive the signal for ac clutch in my log and will stay on all the time until I turn off the car otherwize will run even with heat off


Any idea?? sorry for my bad english i'm a french native and I have a really hard time to explain

 

You have the options set to blowing up onto windshield? You turn fan on, I think the A/C automatically flips on? Kind of a "defrost" or "de-fog" mode.

 

The AC is automatically activated when air is directed to the windshield vents. This is user-settable with a series of switch presses. Defaults back if the battery is disconnected.

How to disable AC when defrost is selected.

-- Chuck

 

Problem with control head/unit. Saw one do exactly same thing.

 

Does he need to replace the unit? Or just fix (reprogram?) it?

Thanks!

 

Verify why it stays on. Data capable scanner not code reader. Identify what is keeping it on and check inputs and outputs. The one I dealt with had faulty chip in module. Rare but does happen .....usually with help from shorting out from external i​​​ssue. Used control units are cheap.

 

Thanks! Be nice if the OP would respond to the suggestions.